International Patent Applications WO 1999/012990, WO 2002/009768, and WO 2002/009767, as well as U.S. Pat. Nos. 6,486,214, 6,613,807, and 6,689,350, discuss biodegradable polymers that have a therapeutic agent incorporated into the polymer backbone. The polymers are reported to be useful materials for forming or for coating medical articles (e.g. devices such as stents), as they degrade and thereby deliver the therapeutic agent to a host.
One potential difficulty encountered with articles formed from such polymeric materials is that, unlike metal articles, the polymeric articles are not visible using X-Ray imaging techniques. Thus, it is not possible to monitor the placement of the polymeric articles during or after implantation into a subject. This limits the practical uses of polymeric articles prepared from these and other polymeric materials.
Accordingly, there is currently a need for materials that can be used to prepare polymeric articles that are visible using X-Ray imaging techniques.